KR0151634B1 - Stable fluid and/or fluidizable cosmetic sunscreening composition, its preparation and its use - Google Patents

Abstract

The present invention relates to metal oxides as photoprotectants in excipients in the form of cosmetically acceptable oil-in-water emulsions having an average size of the globules constituting the oil phase of 100 to 1000 nm, preferably 100 to 500 nm (ultrafine emulsion), more specifically For topical use containing inorganic nanopigments based on titanium oxide, more specifically in the photo-protective cosmetic composition of the skin and / or hair against ultraviolet (UV-A and / or UV-B) and especially sunlight. The present invention relates to a new cosmetic composition further comprising at least one of mixed silicates of alkali metals and / or alkaline earth metals. The composition according to the present invention exhibits excellent stability (no dephase between the water phase and the oil phase and no precipitation of the nanopigments).

Moreover, the present invention relates to a method for stabilizing ultrafine emulsions, a process for preparing these compositions and their use in the cosmetics sector mentioned above.

Description

Stable sunscreen cosmetic composition in liquid and / or liquefied form, method and use thereof

The present invention relates to novel stable liquid and / or liquefiable cosmetic compositions (hereinafter more simply referred to as sunscreen compositions) for the topical use, in particular for the photoprotection of skin and / or hair against ultraviolet rays, their preparation A method and its use in the cosmetic field mentioned above. More specifically, light-protective agents (UV reflectors and / or diffusers), which are provided in the form of oil-in-water emulsions (acceptable excipients for cosmetics) and which have the effect of physically blocking radiation. (Ii) inorganic oxides based on metal oxides, in particular titanium oxides, and stabilizers containing mixed silicates of alkali metals and / or alkaline earth metals. It further relates to a method of stabilizing an oil-in-water emulsion containing nanopigments.

Rays of light between 280 nm and 400 nm burn the human epidermis. Rays of light between 280 nm and 320 nm, known as UV-B, cause skin burns and erythema that aggravate natural burning by sunlight. It is well known that the radiation should be blocked.

It is also well known that UV-A rays at wavelengths between 320 nm and 400 nm, which burn the skin, are particularly susceptible to adverse effects, especially in sensitive skin or in the case of continuous exposure to sunlight. In particular, UV-A rays cause the skin to lose elasticity and cause wrinkles leading to premature aging. They may promote erythema or amplify in some people, causing photo-toxic or photo-allergic reactions. Therefore, it is also desirable to block UV-A radiation.

Many compositions intended for photo-protection (UV-A and / or UV-B) of the skin have been proposed up to now, and inorganic nanopigments based on metal oxides, in particular titanium oxides (in other words their averages) When pigments of injectors generally do not exceed 100 nm in size, when combined with conventional UV blocking agents (mainly organic compounds capable of absorbing harmful premature births), their use is increasingly common, since very high protection is achieved. It is becoming.

Due to a number of related causes, especially as the ease of use is increased (softness, softness, etc.), currently available sunscreen compositions generally are oil-in-water emulsions in which the above-mentioned nanopigments are introduced at various concentrations. (I.e. in the form of excipients consisting of an aqueous continuous dispersion phase and an oil discontinuous dispersion phase), in which other conventional UV blocking agents are suitably combined, these being the aqueous phase and the oil phase (also called the fatty phase) of the emulsion. It may be present in both. In addition, these conventional emulsions containing emulsifiers (or surfactants) and any common cosmetic additives such as fragrances, pigments or preservatives are generally larger in size than several microns.

One of the disadvantages of the known sunscreen compositions belonging to this form (nano pigment containing O / W emulsions), more specifically compositions containing nano pigments of titanium monotide TiO ₂ , is once applied to the skin in the form of a membrane. When applied, it is undesirable for makeup and causes skin whitening effects that users dislike. This effect is more pronounced when the concentration of nanopigments in the emulsion is higher. To avoid this problem, it is of course possible to reduce the amount of nanopigment used, but such emulsions form a transparent film on the skin, which no longer provides adequate protection in the UV region, greatly limiting the value of such manipulations. do.

Moreover, another difficulty is that when applying a conventional sunscreen emulsion based on protective nanopigments to the skin, the distribution of the nanopigments on the skin is uneven, uneven and coarse and thus lowers the overall photo-protective effect. It is a fact that. This poor distribution of nanopigment on the skin is closely related to the fact that the uniformity in the initial emulsion itself (prior to application) is substantially lacking (poor dispersion of the pigment in the excipient).

Recently, in some sunscreen emulsions containing the emulsifiers (surfactants) mentioned above, it has been observed that the preservation state of the once-packed emulsions is poor due to the lack of stability over time. The lack of stability in itself indicates that a rather pronounced precipitation of the nanopigment in the emulsion or separation of the water phase and oil phase in the emulsion (dephase) occurs.

The applicant has already filed a French patent application No. 94 / 01,455, which shows excellent transparency on the skin, excellent protection against UV rays, excellent stability and perfect uniformity (in other words, initial emulsion) before and after application to the skin. An improved O / W type sunscreen emulsion containing inorganic nanopigments based on metal oxides, which are very well dispersed within the nanopigments and well dispersed on the skin after application). Suggested. More precisely, the specific ultrafine O / O is preferably from 100 to 1000 nm, preferably from 100 to 500 nm, in other words within the given range, preferably the average size of the globules constituting the fatty phase, obtained according to the phase transition emulsification technique. The use of W emulsions has shown in the above-mentioned application that the photo-protective nanopigments of conventional O / W emulsions can overcome many of the disadvantages encountered in use. The sunscreen compositions described in Application No. FR 94 / 01,455 are typically in conformity with the following compositions: (i) Water phase: 50 to 95% by weight, preferably 70 to 90% by weight of the total formulation; (ii) oil phase: 5-50% by weight, preferably 10-30% by weight of the total formulation; (iii) Nano pigments: 0.5 to 40% by weight, preferably 1 to 30% by weight of the total formulation: (iv) (Auxiliary) emulsifier: 0.5 to 20% by weight, preferably 2 to 10% by weight of the total formulation. %. The preparation is preferably obtained according to a process according to the process characterized in that it comprises the following essential steps: (a) an emulsified system (polyoxyethylenated and / or polyoxypropylene) suitably selected for obtaining an emulsion in water-in-oil form Non-ionic type of emulsifiers, alone or as mixtures, in hydrated fatty alcohols, and optionally in polyoxyethylenated and / or polyoxypropylenated polyol fatty acid esters, the total HLB is preferably from about 9.5 to 11.5, more Preferably mixed together at a temperature above the phase transition temperature (PIT) of the medium, on the one hand with stirring, in the presence of (a) selected from close to about 10), and (b) Lowering the temperature below the phase transition temperature yields an ultrafine emulsion in oil-in-water form, and (c) performing step (a). After and / or completing step (b), to introduce the inorganic nano-colorant. By equalizing the other factors (i.e., the same concentration and chemical composition) by simply adjusting the size of the oil globules to an appropriate value as indicated above, the sunscreen composition according to the invention associated therewith is the size of the oil globules mentioned above. The French patent application mentioned above demonstrates consistently exhibiting improved properties in terms of transparency, stability, uniformity and protective capacity in the skin compared to the same sunscreen composition which does not satisfy.

Now, as a result of the continuous work in this field, the Applicant has indicated that the composition itself described in patent application FR 94 / 01,455 has disadvantages, in other words that the liquid phase is particularly readily volatilized for the purpose of making a usable product. When it is desired to prepare a composition such as this, it has been observed that it is difficult to always obtain a constant stability over a short or long period, and that this lack of stability itself occurs as a gradual precipitation of nanopigments appears. The object of the present invention is, strictly speaking, to solve the above problem.

Thus, a great deal of research has been conducted on this subject, and ultrafine emulsions based on nano pigments (100 nm < Φ _globule < 1000 nm) have now been applied by applicants to these emulsions simply by adding mixed silicates of alkali and / or alkaline earth metals. We found that it is possible to solve problems such as the lack of stability. When these mixed silicates are added to the ultrafine emulsion, the composition causes precipitation concentration (varies depending on the amount added), but because the mixed silicate is a thixotropic viscous agent, the resulting composition is obtained by mechanical action, for example In fact, it can be easily liquefied by applying shear stress or by diluting with water while stirring or rubbing the product immediately prior to use, or otherwise passing through the pump body of the evaporator. Moreover, all the benefits associated with ultra-fine O / W emulsions based on nano pigments are not impaired by the addition, resulting in excellent transparency in the skin, excellent UV protection efficiency, uniformity before or after use in the skin, and fat The defrosting member between the water phase and the water phase is particularly retained. The general stabilizing effect (no precipitation on one side and no de-phase on the other) caused by the presence of mixed silicates in O / W emulsions based on nano pigments has been found in ultrafine emulsions without these nano pigments. When added, the surprise between the water phase and the oil phase in the emulsion occurs quickly, which is more unexpected.

All these findings are based on the present invention.

Thus, new liquid and / or liquefiable cosmetic compositions, in particular sunscreen compositions, have been proposed which are consistent with one of the objectives of the present invention, and these compositions have an average size of the globules constituting the oil phase from 100 nm to 1000 nm ( In a cosmetically acceptable excipient in the form of an oil-in-water emulsion, which contains inorganic nanopigments based on metal oxides as a light protective agent, and additionally contains one or more mixed silicates of alkali metals and / or alkaline earth metals. Characterized in that.

The object of the present invention is also the stabilization of the ultrafine O / W type containing nano pigments as well as the O / W type containing nano pigments during the actual preparation of the emulsion or after the preparation (emulsion has already been made). Mixed silicates of alkali metals and / or alkaline earth metals are used for a corresponding stabilization process consisting of adding mixed silicates of one or more alkali metals and / or alkaline earth metals to the ultrafine emulsion of.

Another subject of the invention is a specific process for preparing a composition according to the invention.

Other features, aspects, and advantages of the invention will be apparent from the following detailed description.

According to the invention, the term mixed silicates of alkali metals and / or alkaline earth metals means at least two other alkali metals or at least two other alkaline earth metals or at least two alkali earth metals and at least one alkaline earth metal other than silicon and oxygen atoms (silicate units). Refers to a silicate derived from a natural or synthetic substance consisting of metal cations selected from (maintaining overall chemical neutrality). Such silicates have a chemical structure similar to hectorite (natural clay). Preferably, those made of synthetic mixed silicates are used because these products are in fact or near free of impurities, especially silica. Moreover, mixed silicates are known to have precipitate concentration and thixotropic properties.

Mixed silicates containing at least one alkaline earth metal are preferably used.

Even more preferably a mixed silicate containing at least one alkaline earth metal assembled with at least one alkali metal is used.

Alkali metals are preferably selected from lithium, sodium and potassium.

Alkaline earth metals are preferably selected from magnesium and calcium.

According to a particularly preferred embodiment of the invention, one or more magnesium, lithium and sodium mixed silicates are used.

These products are well known to those skilled in the art. In particular, they may be synthesized according to the preparation method of US Pat. No. 3,586,478. Moreover, some of these are commercially available, especially LAPONITE by LAPORTET. (Particularly LAPONITE DS, D, XLS or XLG).

The metal oxides (nano dyes) used in the present invention are all already known as photo-protective activities. They can therefore be chosen in particular from titanium, zinc, iron, zirconium and cerium oxide or mixtures thereof.

Such nanopigments, such as coated or uncoated metal oxides, are already well known to those skilled in the art and are described in particular in patent application EP-A-0,518,773. Additional commercially available nanopigments not mentioned in the above mentioned patents may also be used in the present invention, which are sold under the trade names UVT M 160, UVT M 212 and UVT M 262 from KEMIRA and the trade name MT 100 SAS from TAYCA. Mention may also be made of the product.

According to a preferred embodiment of the sunscreen composition according to the invention, an inorganic nanopigment based on titanium oxide is used which shows the greatest efficiency in photoprotection. It can also be seen that the undesirable cosmetic effect of skin whitening mentioned at the beginning of this specification is especially observed in this type of nanopigment. This titanium oxide may be in crystalline form of rutile and / or anatase type, and / or in amorphous or specific amorphous form. As mentioned above this pigment may or may not be coated, but it is preferred to use a pigment coated with, for example, alumina and / or aluminum stearate.

Depending on the somewhat pronounced lipophilic or converse hydrophilic nature of the nanopigment, it may be present in the fatty phase or the aqueous phase of the emulsion or at the same time on both sides.

The average size of the main pigments of nanopigments present in the composition according to the invention is usually from 5 to 100 nm, preferably from 10 to 50 nm.

Furthermore, of course the sunscreen compositions according to the invention may contain one or more conventional lipophilic or hydrophilic organic sunscreens (absorbers) which are active in UV-A and / or UV-B. For example, such additional blocking agents may be used in the preparation of 2-phenylheximidazole-5-sulfuric acid and salts thereof, such as cinnamic derivatives such as 2-ethylhexyl-p-methoxycinnamate, such as 2-ethylhexyl salicylate and Salicylic derivatives such as homotenyl salicylates, such as 3-(4-methylbenzylidene) camphor or (1,4-divinylbenzene) camphor-camphor derivatives such as sulfuric acid, 2,4,6-tris [p-( 2'-ethylhexyl-1'-oxycarbonyl) anilino]-triazine derivatives such as 1,3,5-triazines, benzophenone derivatives such as 2-hydroxy-4-methoxybenzophenone, 4-t- Dibenzoylmethane derivatives such as butyl-4′-methoxydibenzoylmethane, β, β-diphenylacrylate derivatives such as 2-ethylhexyl α-cyano-β, β-diphenylacrylates, eg octylpara-dimethylamino P-amino-benzoic acid derivatives, such as benzoate, menthyl anthranilate and patent application WO Barrier polymers and barrier silicones described in 93 / 04,665. Examples of other organic blockers are in patent application EP-A 0,487,404.

Since the nature of the fatty phase present in the composition of the emulsion according to the invention is not defined, it may consist of all compounds already generally known to be suitable for the preparation of oil-in-water emulsions. In particular, such compounds may be selected alone or in a mixture from oils of various fat, plant, animal or mineral origin, natural or synthetic beeswax and the like.

Among the oils that may be used in the fatty phase composition are the following substances in particular:

-Mineral oils such as paraffin oil and liquid petrolatum.

Oils of animal origin, such as perhydrosqualene.

Sweet almond oil, avocado oil, castor oil, olive oil, jojoba oil, sesame oil, peanut oil, grapeseed oil, rapeseed oil, coconut oil, hazelnut oil, shea butter, coconut oil, Oils of plant origin, such as apricot seed oil, calophyll oil, rice bran oil, corn germ oil, wheat germ oil, soybean oil, sunflower oil, gold evening primrose oil, safflower oil, zinnia oil and rye oil.

Purcellin oil, butyl myristate, isopropyl myristate, cetyl myristate, isopropyl palmitate, isoflophyll adipate, ethylhexyl adipate, butyl stearate, hexadecyl stearate, isopropyl stearate , Synthetic oils such as octyl stearate, isocetyl stearate, decyl oleate, hexyl laurate, propylene glycol dicaprylate and esters derived from ranolic acids such as isopropyl lanoleate and isocetyl lanoleate, isoparaffins and poly α-olefins.

Other oils usable in the emulsions according to the invention also include C ₁₂ to C ₁₅ aliphatic alcohols (Finsolv TN of FINETEX), 2-octyldodecanol, acetylglycerides as well as lauryl, cetyl, myristyl, stearyl, palmi Benzoates of aliphatic alcohols such as methyl and oleyl alcohols, octanoates of alcohols and polyols such as glycols and glycerol and polyols such as decanoate, cetylisine oleate and lysinelates of alcohols, caprylic / ca Fric triglycerides, triglycerides of fatty acids such as triglycerides of triglycerides of C ₁₀ to C ₁₈ saturated fatty acids, fluorinated and perfluorinated oils, lanolin, hydrogenated lanolin, acetylated lanolin and finally volatile or nonvolatile as silicone oils have.

Of course, the fatty phase may also contain one or more conventional lipophilic cosmetic auxiliaries, specifically those typically used in the manufacture and production of sunscreen compositions already used in cosmetics.

According to an important feature of the invention, the average size of the liquid particles (or globules) of the fatty phase in the aqueous dispersed phase should be in a very specified range, ie 100 nm to 1000 nm. Preferably this average size is from 100 nm to 500 nm. More preferably, the size distribution of the oil globules is such that the size of most of the foregoing globules (ie, at least 90% from a numerical point of view) lies between the above mentioned limits.

The aqueous dispersion phase in the conventional manner may consist of water or a mixture of water with polyhydric alcohols such as glycerol, propylene glycol and sorbitol, or alternatively a mixture of water-soluble lower alcohols such as ethanol, isopropanol or butanol (aqueous alcohol solution) and water. Naturally, it may also contain a conventional water-soluble cosmetic adjuvant.

Among the conventional cosmetic auxiliaries which may be contained in the fatty phase and / or the water phase of the emulsions (by water-soluble and / or fat-soluble properties) according to the invention are specifically ionic or nonionic thickeners, protective agents, antioxidants, opacifying agents. , Stabilizers, emollients, insect repellents, hydrating agents, vitamins, perfumes, preservatives, fillers, metal ion sequestrants, colorants or any other ingredients commonly used in the field of sun protection products.

The emulsions according to the invention also generally contain emulsifiers for which certain surfactants or their uses are required for the preparation and obtaining of ultrafine emulsions. This will be explained in detail below. This emulsion may also contain certain auxiliary emulsifiers, the role of which is to specifically reduce the amount of surfactant needed to produce the emulsion during the emulsion formulation.

As a guide, sunscreen preparations according to the invention generally comprise the following composition.

(i) Water phase: 50 to 95% by weight of the total formulation, preferably 70 to 90% by weight.

(ii) oil phase: 5-50% by weight of the total formulation, preferably 10-30% by weight.

(iii) Nano pigments: 0.5-40% by weight of the total formulation, preferably 10-30% by weight.

(iv) mixed silicate (s): 0.05-5% by weight of the total formulation, preferably 0.1-3.5% by weight.

(v) (secondary) emulsifier (s): 0.5-20% by weight of the total formulation, preferably 2-10% by weight.

They also preferably have a viscosity of 15,000 cps or less, more preferably 5000 cps or less (measured with 5 discs at 15 rev / min with a Brookfield RVT model DV2 viscometer).

Stable compositions according to the invention may be prepared by known production processes which comprise the introduction of mixed silicates of alkali metals and / or alkaline earth metals into ultrafine O / W emulsions which essentially contain nanopigments. Thus, they introduce mixed silicates or silicates into prefabricated ultrafine emulsions (primary strains), which may themselves be obtained by any known method (ultrasound, high pressure mixer / homogenizer, phase change, etc.), Or by adding a silicate introduction step to one or more of the known production process steps for the preparation of the ultrafine emulsion (secondary modification). In the latter case, the resulting emulsion differs from the emulsion produced by a known production method that does not use silicate, in which only silicate is present in the emulsion.

From the above, it is sufficient to use a conventionally known production method for the production of ultrafine O / W emulsions containing nano pigments known to lead to an emulsion having the desired properties, but the desired chemical composition (except silicate) and structural properties It can be seen that in order to obtain an emulsion according to the present invention having an additional silicate introduction step must be added. Corresponding such rules between silicate-free emulsions and emulsion-containing emulsions clearly apply similarly to the primary strains summarized above.

Notwithstanding the foregoing, particularly preferred methods of preparation for the preparation of the compositions according to the invention will be presented below.

This method is based on the description of O / W emulsion formulations by phase transition. The principles of this technique are well known to those skilled in the art, and are specifically described in 1991 Cosmetics and Toiletries Vol. 106 PP. The phase change by author T. Forster et al., 49-52, has been published in the emulsification column. Thus the principle is as follows: The emulsion must be prepared (injecting water into the oil) at a temperature above the phase transition temperature of the system (ie PIT). That is, the temperature at which the balance between hydrophilic and lipophilic is used: at high temperatures (> PIT), the emulsion is in water-in-oil form, and as it cools, the emulsion transitions from microemulsion to an oil-in-water emulsion. .

According to the present invention the nanopigments should be present in the final ultrafine O / W emulsion. Thus, according to a first embodiment of the formulation method implementation according to the invention, the phase transition of the emulsion is carried out in the presence of the photoprotective nanopigments described above: According to a second embodiment of this method, these nanopigments are obtained by emulsions obtained from phase transitions. It is added immediately after it is obtained. It is of course also possible to use both implementations simultaneously.

According to the above mentioned primary and secondary variants, the mixed silicates themselves are added in the medium during the actual stage of carrying out the phase transition (primary variant) or preferably after completion of this step (secondary variant). It may be. In this case, two deformations may also be performed simultaneously.

One of the difficulties in carrying out such a manufacturing method is to properly select an emulsifying system suitable for the desired result.

Therefore, the emulsifying system to be used in the present invention is to obtain a stable ultrafine emulsion (100 nm < phi _globule < 1000 nm) which is actually obtained from the phase transition, so that the nano pigments in the emulsion can be finely and uniformly dispersed.

Applicant's study suggests that, in the end, suitable emulsifiers for the present invention should be emulsifiers in nonionic form, more specifically polyoxyethylenated and / or polyoxypropyleneated aliphatic alcohols (ie aliphatic aliphatic such as behenyl or cetyl alcohol). Compounds obtained by reacting alcohols with ethylene oxide or propylene oxide or ethylene oxide / propylene oxide) and fatty acid esters of any polyoxyethylenated and / or polyoxylated polyols (ie, fatty acids such as stearic acid or oleic acid). For example, a compound obtained by reaction with a polyol such as alkylene glycol or glycerol or polyglycerol in the presence of ethylene oxide or propylene oxide or an ethylene oxide / propylene oxide mixture), or mixtures thereof. More specifically adopted emulsification systems have a total HLB between about 9.5 and 11.5 and preferably close to 10 HLB, as known, HLB means a balance of hydrophilic-lipophilic in the Griffin sense (see J. Soe. Cosm, Chem. 1954 (Vol. 5) pp 249 Remaining 256) Indicates the balance between the hydrophilic and lipophilic properties of the surfactant. This allows phase transitions to occur at temperatures below 90 ° C (PIT <90 ° C).

Surprisingly and unexpectedly, the presence of inorganic nanopigments in the emulsified initial system never interferes with the mechanisms that are naturally involved in the phase-transfer emulsification process: rather, ultrafine emulsions are characterized by the finely dispersed state of the particles themselves that make up the nanopigment (in the absence of aggregates or Very small aggregates), which are completely uniform and stable in time.

Detailed formulation methods according to the present invention will be apparent in the following examples.

A third subject of the invention is as described above for the preparation of a composition of human epidermis or hair protection against UV irradiation or as a sunscreen composition, for the preparation of a composition according to the invention or as a sunscreen composition, To a use of the composition according to the invention. The compositions can thus be formulated in the form of creams, milks, cream gels or liquid lotions, in particular liquid lotions which evaporate (the composition according to the invention has advantageous additional properties in fact very easy to dilute with water).

As a protection against the effects seen in UV irradiation, specifically solar irradiation, the method of handling skin or hair cosmetics is to use the above-mentioned effective amount of the cosmetic composition therefor.

Specific but non-limiting examples to illustrate the invention are as follows.

EXAMPLE

Various ultrafine emulsions (Φ _globule <1 μm) (formulations F1 to F7) with or without nano pigments and / or mixed silicates of TiO ₂ are prepared and compared (by phase transfer techniques).

In the case of the nanopigments, the starting materials used are as follows.

-Nano pigmented titanium oxide TiO ₂ (sold under the name MT100T by TAYCA)

Or nano pigmented titanium oxide TiO ₂ (sold under the name RIOVEIL AQ by TIOXIDE)

The mixed silicate used is a mixed silicate of magnesium, lithium and natrium sold under the trademark LAPONITE XLG by LAPORATE.

The chemical component ratios (expressed in weight percent of the total formulation) of these formulations are as follows (see Table I below):

Phase A:

3.3% cetyl / stearyl alcohol with 12 moles of ethylene oxide

(ENUMEL's EUMULGIN B1)

-Glyceryl Stearate 1.7%

(TEGIN 90 in GOLDSCHMIDT)

-Hydrogenated polydecane 10%

(ETHYL FLO 362 NF by ETYYL CORP)

-Octylcyclohexane 6%

(Cetiol S of HENKEL)

-Cyclomethicone 4%

Phase B:

Titanium oxide TiO ₂ 0-5%

Phase C:

Mixed silicates 0-3.5%

Phase D:

Glycerol 3%

-Water qs 100%

Phase E:

-Preservative qs

The procedure performed to prepare these agents is as follows:

Both the fat phase (A) and the water phase (C) are previously adjusted to a temperature of 90 ° C; The phase (B) containing the nanopigment MT 100 T is then injected and dispersed in the fat phase (A) by a MORITZ type turbo mixer (1000 rpm): the aqueous phase (D) is then added to the dispersion obtained with mechanical stirring. do. This emulsification is carried out at 80 ° C., i.e., above the phase transition temperature of the system; Number of phases observed to occur by bringing the temperature of the medium to about 40 ° C., phase (B) containing the pigment TIOVEIL AQ was added to the obtained ultra-fine emulsion, and phase (C) previously dispersed in water at 60 ° C. Finally add to phase (E).

For each of the formulations thus obtained, the stability on storage was observed at room temperature on the one hand and at 45 ° C. on the other hand to determine if deaeration between the aqueous and oil phases of the emulsion occurred (i) and / or the emulsion pigment precipitated (ii). Evaluated.

The results are shown in Table 1 below. OK in this table means that no dephase and precipitation occurred after 2 weeks of storage.

These results clearly demonstrate that the formulations F5 to F7 according to the invention are excellent in terms of stability.

Claims (37)

Coated or uncoated titanium, zinc based on metal oxides as light protective agents in cosmetically acceptable excipients in oil-in-water emulsion forms with an average size of the globules constituting the oil phase from 100 nm to 100 nm (nanometers). In the topical cosmetic composition containing inorganic nanopigments selected from oxides of iron, zirconium, cerium, and mixtures thereof, at least one mixed silicate of two or more metals selected from lithium, sodium, potassium, magnesium and calcium is added. Cosmetic composition for topical use, characterized in that it contains. The composition of claim 1 wherein the average size of the oil globules is between 100 and 500 nm. The composition of claim 1 or 2, wherein at least 90% of the oil globules have a size between 100 and 1000 nm. The composition according to claim 1 or 2, wherein the average size of the main particles constituting the nano pigment is 5 to 100 nm. The composition of claim 4 wherein the average size is 10-50 nm. The composition of claim 1 or 2, wherein the composition is based on titanium oxide coated with or without nanopigmentation. 7. The composition of claim 6, wherein the titanium oxide is in rutile, anatase or amorphous form. The composition according to claim 1 or 2, further comprising at least one organic sunscreen which is active on UV-A, UV-B or both. The composition of claim 1 or 2, which also contains one or more emulsifiers. 10. The composition of claim 9, wherein the content of emulsifier (s) is from 0.5 to 40% by weight relative to the total weight of the composition. The method according to claim 1 or 2, wherein the ionic or nonionic thickeners, protective agents, antioxidants, opacifying agents, stabilizers, softeners, insect repellents, wetting agents, vitamins, flavors, preservatives, fillers, metal ion sequestrants and A composition comprising also one or more adjuvants selected from colorants. The composition according to claim 1 or 2, wherein the weight content of the aqueous phase is 50 to 95% of the total weight of the composition. The composition according to claim 1 or 2, wherein the weight content of the oil phase is 5 to 50% of the total weight of the composition. The composition of claim 1 or 2, wherein the weight content of the nanopigment is 0.5 to 40% of the total weight of the composition. The composition according to claim 1 or 2, wherein the weight content of the mixed silicate is 0.05-5% of the total weight of the composition. The composition according to claim 1 or 2, wherein the alkali metal or metals present in the composition of the mixed silicate is selected from lithium, sodium and potassium. A composition according to claim 1 or 2, wherein the alkaline earth metals present in the composition of the mixed silicate are selected from magnesium and calcium. The composition according to claim 1 or 2, wherein the mixed silicate is selected from mixed silicates containing at least one alkaline earth metal. 19. The composition of claim 18, wherein the mixed silicate also contains one or more alkali metals. 20. The composition of claim 19, wherein the mixed silicate is a mixed silicate of magnesium, lithium and sodium. In the oxides of titanium, zinc, iron zirconium, cerium, and mixtures thereof, the average size of the globules constituting the oil phase is from 100 nm to 1000 nm (nanometers) and is based on metal oxides as light protective agents. At least one mixed silicate of at least two metals selected from lithium, sodium, potassium, magnesium and calcium is added to the previously prepared or in-process emulsion in the oil-in-water form containing the selected inorganic nanopigment. A process for preparing a composition as defined in any one of claims 1 to 20. 22. The oil-in-water emulsion according to claim 21, wherein (i) the fat phase on the one hand and the water phase on the other hand are mixed with stirring in the presence of a suitable emulsification system, but at a temperature above the phase transition temperature (PIT) of the medium. and ; (ii) lowering the temperature of the obtained emulsion to a temperature below the phase transition temperature to obtain an emulsion in the form of ultrafine oil-in-water; (iii) introducing inorganic nanopigments, mixed silicates or both during the performance of step (i), after completion of step (ii) or after completion of step (i) and completion of step (ii). Method for producing a composition characterized by. 23. The method of claim 22, wherein the silicate is introduced after completion of step (ii). 24. The method according to claim 22 or 23, wherein the emulsifier or emulsifiers are of a nonionic type, polyoxyethylenated, polyoxypropyleneated or polyoxyethylenated and polyoxypropyleneated aliphatic alcohols and polyoxyethylenated, polyoxypropylene And a mixed form of one selected from fatty acid esters of polyols which may be converted or polyoxyethylenated and polyoxypropyleneated. The method of claim 24, wherein the emulsifying system has a total HLB of 9.5 to 11.5. At least one mixed silicate of two species of metals selected from lithium, sodium, potassium, magnesium and calcium is introduced into the emulsion during synthesis of the emulsion, after synthesis of the emulsion, or after synthesis of the emulsion and after synthesis of the emulsion. Oxides of titanium, zinc, iron, zirconium, cerium and the like, having an average size of the globules constituting the oil phase of 100 nm to 1000 nm (nanometers) and based on a metal oxide as a light protecting agent; A method of stabilizing an oil-in-water emulsion containing an inorganic nanopigment selected from the mixture of. An optical protective agent containing inorganic nanopigments selected from oxides of coated or uncoated titanium, zinc, iron, zirconium and cerium based on metal oxides and mixtures thereof, the average size of the globules constituting the oil phase is 100 nm. A method for stabilizing an oil-in-water emulsion of from 1000 nm to 1000 nm, wherein at least one mixed silicate of two or more metals selected from lithium, sodium, potassium, magnesium and calcium is added. The cosmetic composition according to claim 1 or 2 for protecting the skin or hair from UV radiation. The composition of claim 1 for photoprotection of skin or hair. 4. The composition of claim 3, wherein at least 90% of the oil globules have a size of 100 to 500 nm. 12. The composition of claim 11, wherein the content of emulsifier (s) is from 2 to 10% by weight relative to the total weight of the composition. 13. The composition of claim 12 wherein the weight content of the aqueous phase is 70 to 90% of the total weight of the composition. The composition of claim 13, wherein the weight content of the oil phase is 10-30% of the total weight of the composition. 15. The composition of claim 14, wherein the weight content of nanopigments is 1 to 30% of the total weight of the composition. The composition of claim 15 wherein the weight content of the mixed silicate is 0.1-3.5% of the total weight of the composition. The method of claim 25, wherein the emulsifying system has a total HLB of close to ten. The cosmetic composition of claim 28 for protecting the skin or hair from sunlight.